Wireless communications networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources.
A wireless communications network may include a number of access points. The access points of a cellular network may include a number of base stations, such as NodeBs (NBs) or evolved NodeBs (eNBs). The access points of a wireless local area network (WLAN) may include a number of WLAN access points, such as WiFi nodes. Each access point may support communication for a number of user equipments (UEs) and may often communicate with multiple UEs at the same time. Similarly, each UE may communicate with a number of access points, and may sometimes communicate with multiple access points and/or access points employing different access technologies. An access point may communicate with a UE via downlink and uplink. The downlink (or forward link) refers to the communication link from the access point to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the access point.
Operators of cellular networks, referred to herein as operators, may have exclusive rights to some portion of the licensed spectrum, and may deploy a number of base stations and other network elements to provide access to the operator network through the licensed spectrum. A UE associated with the operator may gain access to the operator's network through security credentials that are associated with the UE. For example, a UE may include a Subscriber Identity Module (SIM) card that may include an International Mobile Subscriber Identity (IMSI) and one or more key for use in identification and authentication of subscribers of the operator. UEs that are associated with an operator may not be authenticated as subscribers on another operator's network, and may access the other operator's network through roaming procedures, for example.
As cellular networks become more congested, operators are beginning to look at ways to increase capacity. One approach may include the use of WLANs to offload some of the traffic and/or signaling of a cellular network. WLANs (or WiFi networks) are attractive because, unlike cellular networks that operate in a licensed spectrum, WLANs may operate in an unlicensed spectrum. In some deployments, WLANs may be configured to operate according to protocols of a cellular network. Because such WLANs may operate in an unlicensed spectrum, this provides the possibility that network access may be provided through such WLANs by non-operators. That is, a company that does not have any rights to licensed spectrum, or does not have rights to licensed spectrum in a particular geographic area, may provide access to UEs through unlicensed spectrum.